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Motivated by the need for robust and high throughput communication with airborne platforms, a variable rate MIMO scheme that combines the D-BLAST architecture with per antenna spreading was proposed. This paper is focused on the experimental study of this approach. We developed a software defined radio implementation of the variable rate MIMO system based on GNU Radio. Over the air transmission and...
In this paper, a multi-pair amplify-and-forward (AF) massive MIMO system is investigated, where multiple source users communicate with multiple destination users via a single relay. The achievable rate of the system and its analytical expression are studied for power-scaling laws when ZFT/ZFR algorithm is adopted at the relay. The imperfect channel state information (CSI) is considered and the MMSE...
A multi-pair amplify-and-forward (AF) MIMO system is considered in this paper, in which all source users transmit their information to destination users via a shared relay. With the large N regime, the effect of small-scale fading tends to diminish while the large-scale fading plays a main role in affecting the system performance. The large-scale fading is modeled as generalized-K fading. While the...
The influence of the person density on the indoor MIMO channel models is experimentally investigated. The path loss is modeled as a log-distance function adding additional attenuations related to both of the distance and person density. Then, the shadowing, the root mean square delay spread, and the channel capacity are described as normal distributed random variables. Their mean value and the standard...
In this paper we present the performance evaluation for a MIMO in vivo WBAN system, using ANSYS HFSS and the associated complete Human Body Model. We analyzed MIMO system capacity statistically and FER performance based upon an IEEE 802.11n system model, with receiver antennas placed at various angular positions around the human body. We also analyzed MIMO system capacity with receiver antennas at...
Multiple Input Multiple Output (MIMO) system is considered as an unalterable technology in wireless communication for its advantages in the spectral efficiency. Among the detection algorithms, maximum likelihood (ML) detection can achieve the best bit error rate performance, but the computational complexity of ML detection is too huge to be acceptable. In order to solve this problem, numbers of algorithms...
We present the performance of MIMO for in vivo environments, using ANSYS HFSS and their complete human body model, to determine the maximum data rates that can be achieved using an IEEE 802.11n system. Due to the lossy nature of the in vivo medium, achieving high data rates with reliable performance will be a challenge, especially since the in vivo antenna performance is strongly affected by near-field...
This paper considers a multi-input multi-output (MIMO) wireless relay network, where the source S communicates wirelessly to the destination D via the help of a nonregenerative relay R. Previous studies are almost exclusively based on the assumptions of equal time-duration phases for S-R and R-D transmission and equal number of multiple antennas for every node, and the results concerning arbitrary...
This paper proposes an efficient method for optimal joint precoding-postcoding design in a multi-input multi-output (MIMO) multi-sensor noisy observation context — a problem that is of great interest to the multi-relay MIMO transmission system. A set of wireless sensors, each provisioned with a different number of antennas and a different power constraint, precode and send their noisy observations...
A novel empirical path loss model for indoor stairwell environment is presented. The model is based on the multiple-input-multiple-output (MIMO) measurements at 2.6 GHz. The model is divided into two scenarios, i.e., line-of-sight (LOS) and non-LOS (NLOS). In the case of LOS, the path loss exponent n is dependent with the increasing of frequency slightly and is fitted by the frequency using power...
A novel MIMO model based on singular value decomposition of matrix is proposed in this paper. A corridor to stair MIMO measurement at 2.6GHz is conducted in order to evaluate the performance of the novel model. The joint DoA-DoD-delay power spectrum and the channel capacity of the model are compared with those obtained from the measured channels. The results show clearly that the joint DoA-DoD-delay...
In this paper, the truncated singular value decomposition expectation-maximization (TSVD-EM) based channel estimation on single transmit antenna transmission is extended to transmit diversity transmission. Particular attention is given to Long Term Evolution (LTE) systems. In order to obtain the received symbols for each transmit antenna, an approximation is proposed by using the soft symbols and...
MIMO (Multiple-Input-Multiple-Output) is a promising structure for wireless communication. While virtual MIMO structure has been proposed for distributed and cooperative wireless networks, this proposed structure has also put additional energy consumption where energy stands in the important position. At the same time, we have observed that this-problem-caused low energy nodes' mibehavior will degrade...
In this paper, we propose two novel HARQ schemes based on dual-stream joint beamforming for long term evolution (LTE) advanced system. As one of the most competitive techniques, dual-stream beamforming can achieve multiplexing gain together with beamforming gain. In this paper, algorithm for beamforming vectors is investigated and two novel HARQ schemes are proposed on this basis to further increase...
Efficient implementation of FIR (finite-impulse-response) equalizers for wireless channels has attracted much attention these days as equalizations can improve the link performance in hostile mobile radio environment by compensating for inter-symbol interference created by multipath within time dispersive channels. Meanwhile, the MIMO (multiple-input-multiple-output) technique becomes a trend in wireless...
DSTBC (differential space-time block coding) system does not require CSI (channel state information) in both transmitter and receiver sides, but its SNR (signal to noise ratio) versus BER (bit error rate) characteristic is degraded compared with original STBC scheme which utilizes CSI at the receiver. In this paper, attempting to recover this performance loss originated from the differential decoding,...
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